Things have been a little slow on the Surface Pro and
Windows tablet front the last couple of weeks, but that should all change
beginning next week with the big reveal from Wacom, the eventual release of
Samsung’s ATIV Q, Windows 8.1 and eventually the Surface 2.

In the meantime, I’ve been spending the last couple of weeks
with my new favorite software Manga Studio 5, trying to learn the ins and outs
of 3d modeling for it. Don’t judge me for focusing on 3d in a paint program,
but I just naturally gravitate towards the least documented aspects of any
software I use. All the digging and trial and error are just forms of
procrastination to avoid real work.

Smith Micro is currently in talks with Manga Studio’s
Japanese developers Celsys about whether to publish their new Clip Studio
Modeler software as an English language companion product or add-on to Manga
Studio. The software is currently available as a free beta from the Celsys site
and a user has published a rudimentary English translation if you’d like to
check it out for yourself.

Clip Studio Modeler beta - Coming soon to Manga Studio family?

Manga Studio Modeler, or whatever it ends up being called, will probably be the preferred method for creating or modifying 3d materials
for future versions of MS, but in the meantime, I thought I’d focus on tools
that I’m familiar with. [UPDATE: Although the fan-made translation leaves a lot to be desired, I've spent enough time with the 0.9 beta of CS Modeler to surmise that it is a very limited 3d app and will require a lot of polish before it can be used to model 3d characters.]

3D is a huge, complicated and frankly messy subject matter.
Once you understand the basics and know where to find the features you need in
a particular tool it’s not so bad. But the moment you need to move content from
one application to another, you can be opening up a hornet’s nest.

I’m going to try to keep this series of posts as simple and
generic as possible. I will point to some specific tools that I use, but you
should be able to reproduce these steps with just about any 3d software. Each
tool has its strengths and weaknesses, but it all generally comes down to
personal preference and budget.

The 3D Canvas

Some of this will sound like math and I’m very sorry for
those of you whose minds turn to mush at the very thought of math.

With a paint program like Manga Studio, you’re accustomed to
working on a two-dimensional plane that can be described by a horizontal (x)
dimension and a vertical (y) dimension.

3D adds a perpendicular plane that defines the vertical (y)
and depth (z). In the image below, the ground plane is lying on the x (horizontal) and z (depth) plane.

Visualizing the 3d workplane

In the image above, the cube mesh is defined by 8 points or
vertices. (Only 7 locations are visible in this image. The last vertex is
hidden by the front facing surfaces.)

Each side of the cube is composed of one quadrangular
polygon or face. Each quad is defined by four vertices. The quad polygon can be
subdivided into two triangles. Each vertex can be identified by its x, y and z
coordinate.

Object Types

There are two types of 3d materials or objects to consider:
static or articulated meshes.

As its name indicates, a static mesh doesn’t have any moving
parts and is probably what you will import most often. Examples of static meshes are props, scenery
and backdrops, like a pencil, a desk or a classroom. Articulated meshes, such
as the 3d characters included in Manga Studio, have moving parts that you can
pose.

File Formats - OBJ

Every 3d software writes its own file format, but a couple
of these formats have been around long enough to become “universal.” The most
common of these is OBJ. Because this format goes all the way back to the dawn
of computer animation, it is the most basic.

OBJ models contain no
animation information and are always static.

An OBJ file is simply an ASCII text file that lists the x, y
and z coordinates of every vertex (v) in a mesh.

Here’s the first few lines of an OBJ file for the cube mesh:

# XSI Wavefront OBJ Export v3.0

# File Created: Sat Aug 17 04:17:07 2013

# XSI Version: 12.1.99.0

mtllib
cube.mtl

o cube

# Hierarchy (from self to top father)

g cube

#begin 8 vertices

v 0.000000 0.000000 0.000000

v 1.000000 0.000000 0.000000

v 0.000000 1.000000 0.000000

v 1.000000 1.000000 0.000000

v 0.000000 0.000000 1.000000

v 1.000000 0.000000 1.000000

v 0.000000 1.000000 1.000000

v 1.000000 1.000000 1.000000

#end 8 vertices

You’re not going to need to edit an OBJ file except to determine the
name of its material library. In the cube example above, the mtlib associated
with the mesh is called cube.mtl. Manga
Studio will allow you drag an OBJ file directly onto its canvas, but without an
accompanying MTL file, the mesh will render as a solid gray with no textures.

Unfortunately, while there are many thousands of free OBJ files available
for you to download online, they often don’t have an MTL file. For these files,
the only way to apply materials is to load them into a 3d program, add color
and textures and re-export them with a new MTL file.

The MTL file

The MTL for a given object is also a simple ASCII text file. Here is
the cube.mtl referenced in the cube.obj file:

newmtl
scene_material

Ka 0.300000 0.300000 0.300000

Kd 0.700000 0.700000 0.700000

Ks 1.000000 1.000000 1.000000

Ns 50.000000

Tr 0.000000

illum 2

Newmtl defines the name of the material applied in the 3d application.
In the above example, it’s Softimage’s default scene_material.

newmtl
material

Ka 0.257000 0.000000 0.000000

Kd 0.698000 0.000000 0.000000

Ks 1.000000 1.000000 1.000000

Ns 50.000000

Tr 0.000000

illum 2

In this example, the scene_material has been replaced by material.

newmtl red

Ka 0.257000 0.000000 0.000000

Kd 0.698000 0.000000 0.000000

Ks 1.000000 1.000000 1.000000

Ns 50.000000

Tr 0.000000

illum 2

newmtl
Polygon_XSIPOLYCLS.map

Ka 0.300000 0.300000 0.300000

Kd 0.700000 0.700000 0.700000

Ks 1.000000 1.000000 1.000000

Ns 50.000000

Tr 0.000000

illum 2

map_Kd
BlueGrid.png

This example has two materials: one named “red” and another named “map,”
which is applied to one sub-group, or cluster of the cube (Polygon_XSIPOLYCLS).
The most important entry to note here is the map_Kd item, which identifies the
name and location of the texture required by the map material.

When you download an OBJ and MTL, you will also need to download or recreate any image texture files referred to in the object’s material library.

Texture files must be zipped in the same folder as obj and mtl files. Make sure that mtl is edited to reflect this path for textures.

When importing into Manga Studio, the obj, mtl and textures should all
be zipped in the same directory. You will
need to edit your MTL with a text editor to reflect this. In other words,
if the map_Kd entry above read textures/BlueGrid.png, you would need to remove
the reference to the textures folder.

The diffuse texture is an image file that determines the color of faces
to which it is applied. If the diffuse texture referred to in an MTL file is
missing, the corresponding faces that use that material will render grey.

Manga Studio doesn’t understand any references to specular, bump or
other common textures. Make sure to edit those out of the MTL file or your object
won’t render properly.

So now that you know a little about OBJs and the way Manga Studio
interprets their materials, you should be able to import any static mesh you
create or find online, using the process I wrote about here and that MS artist
and trainer extraordinaire Doug Hill demonstrated in his video here.

File formats – FBX

FBX, short for Filmbox, was a format created for the importation of 3d
objects for motion capture. Filmbox was purchased by Autodesk who market the
product as Motion Builder. The FBX format is constantly being updated and has
become the de facto standard for sharing data between 3d applications and game
engines.

The problem with FBX is that it is managed by Autodesk and is not an
entirely open standard. Developers (including some within the Autodesk family)
are always having to play catch-up with semi-annual releases that often break
the previous version.

FBX can be such a hassle that sometimes a file that plays perfectly in
one application will look badly mangled or worse refuse to load altogether in
another. As an example, when I first started writing this post, I thought I
would use the free DAZ Studio 4.6 to demonstrate the creation of FBX files, but the
files it currently generates are not compatible with the recently released Autodesk FBX
Review, which I discussed here.

I'm not saying that FBX is totally broken. Depending on the source, it does work, and Manga Studio understands it, but I’ll save that for
another article once I’ve found a reliable pipeline that is also affordable.

Rigging and Skinning an OBJ

If you’re modeling your own character to pose, it may take some effort,
but every 3d application will eventually generate a flavor of FBX that Manga
Studio will be able to read. If you’re
not a modeler or can’t invest the time to build a character from scratch, you’re
not entirely out of luck.

Whether a mesh is available for free or paid, there Is no guarantee
that it will work without some intervention on your part. Quality varies widely
and products produced over the years may no longer be 100% compatible with
current tools. In the example screenshots below, I used a Spider-Man mesh that I found on TF3DM, but it was composed of several different objects that I needed to combine. It also had specular and bump maps that I discarded. Had I kept them in the file, the mesh would render as grayscale.

Assuming you have found an OBJ you like, cleaned up its MTL file and
accompanying textures and gotten it to load correctly in Manga Studio, the
next step is to make it poseable.

To do this in a 3d application, you create or bring in a pre-made
skeleton (rig) and attach or skin it to your mesh. Every software
does this differently, so you will need to research this on your own.

For those of you who don’t own a 3d app or want a shortcut, there is a
free (until September) option. Mixamo is a service designed for game artists
who want to quickly apply motion captured animations to their game characters.
In addition to working with already rigged meshes, Mixamo also features an amazing
auto rigger that works great and is absolutely free to use for the next few
weeks with meshes under 10,000 polygons.

After you create an account, upload your zipped OBJ, MTL and textures
to the auto rigger.

Markers assigned with symmetry on.

You will then assign markers to define the object’s chin, wrists,
elbows, knees and groin. Mixamo automagically will do the rest.

To test the results, you can see your mesh performing various animations, including an all-important rigging stress test. Above is a screengrab of the rigged Spider-Man mesh performing a standard run. If you’re happy with the results, you can download the resulting FBX file for free.

The Mixamo FBX output loaded and posed in Manga Studio 5

Simply zip up your Mixamo FBX file and its corresponding textures and drag this archive onto Manga Studio and you now have a working
poseable character.

Mixamo is a great service and is obviously a huge timesaver for
professional game artists. Unfortunately, it’s All-Access annual plan is quite expensive for only
occasional use. I recommend taking advantage of the remaining weeks of free
availability and I will research any other low cost alternatives I can find. If
you know of any, please leave a comment in the section below.

One obvious alternative is the free and open-sourced Blender. This is a very robust application that should be able to handle the entire 3d modeling, texturing, rigging, skinning and exporting process for you. However, it can be quite daunting to learn and I've never taken the time to use it. If any of you are Blender users and would like to contribute a post or video, I and the entire Manga Studio community will thank you.

* * *

So there you have it: more than you probably ever wanted to know about 3d, OBJ and MTL and a simple, free (for a limited time) way to get poseable 3d characters in your Manga Studio projects. I'd like to do more of these types of posts in the future, but I'd really appreciate your feedback on how basic or technical to make them. I look forward to reading your reactions and seeing how you apply these 3d assets in your upcoming Manga Studio projects.